The Diffusion Group reports that, based on their latest research, 11% of adult broadband users (some 12 million US consumers) listen to podcasts at least once per month. They also predict that the podcast audience will more than double in the next five years, to 24% of broadband users (38.5 million Americans) by 2012.

While the audience for podcasting continues to expand, TDG identifies two specific factors that are keeping a lid on usage:

• Podcasting continues to be perceived as too complex for average consumers to use; and
• People remain unaware of the quantity and quality of content available for podcast consumption.

While TDG’s conclusions¬†may seem obvious to¬†most podcasters, they¬†confirm¬†the opportunities still available in the world of podcasting.¬†

“Despite the fact that the Oxford University Press selected ‚Äòpodcast‚Äô as Word of Year in 2005, most consumers have a very poor understanding of the medium or the variety of content available for consumption by podcast,‚Äù said Dale Gilliam III, director of primary research and author of the report.

This lack of understanding, notes Gilliam, is due primarily to the multiplicity of ways in which pundits and marketers have used the term.

Why is the definition of “podcasting”¬†so important? Gilliam continues: ‚ÄúAt the end of the day, the way consumers come to understand a new medium such as podcasting will strongly determine the types of experiences and value they attribute to the concept. When those in the business of articulating and promoting this new medium use language inconsistently, the power of the concept to attract and engage users is diluted.‚Äù

In our experience, much of the misinformation about podcasting has come from tech pundits, analysts and marketers, who have used the term podcasting to discuss anything that has to do with digital media downloads.

Other key findings of TDG’s new report:

• Among those that listen to podcasts at least once per month, 68% use a portable device while 49% listen to them on a PC (an interesting insight given that many define podcasting as only a portable medium);
• On average, users listen to 5.4 podcasts per month on a portable device and 4.7 on a PC;
• On average, those who subscribe to podcast services are signed up for 4.1 different feeds; and
• 70% of users rely on iTunes to access podcasts.